zkCommonGround by Hashchat

Screenshots

Problem Statement

When buying something, deals get stuck in determining where tostarton price negotiations. Often people just walk away due to the "first offer dilemma" of not wanting to feel at a disadvantage. Using a zero knowledge proof, we allow a buyer to submit their "never to be disclosed" best price and the seller to do the same, also never to be disclosed. The only result is whether there is a deal or no deal. The follow-on negotiations can start at the midpoint (if both sides agree to disclose that) or it could be selected randomly within the zone of possible agreement.

Solution

We used react on the frontend to manage the UI and Rainbow wallet. The backend, for now, was deployed using low-level cryptographic tools on python to deploy a version of yao millionaires problem using RSA public keys. This was easiest to get the zk proof up and running on a REST API for interacting with the client browser. Design was done in figma and slides done using google slides.